Which condition is characterized by the presence of "blebs" in the lungs due to smoking?

Emphysema is characterized by the presence of "blebs," which are small air-filled spaces that develop in the lung tissue as a result of the destruction of alveoli. This destruction leads to a reduction in the surface area available for gas exchange, making it difficult for individuals with emphysema to breathe effectively. The blebs can result from the breakdown of lung tissue caused by chronic exposure to irritants, particularly tobacco smoke.

In emphysema, the loss of elasticity in the lungs also causes air to be trapped, leading to hyperinflation, which can be visualized as an increase in lung volume on imaging studies. Patients with emphysema often display characteristics such as a decrease in respiratory function and a "pink puffer" appearance, as they may hyperventilate to maintain adequate oxygen levels despite their obstructed airflow.

Other conditions listed do not typically feature the presence of blebs in the same way. Chronic bronchitis primarily involves inflammation and mucus production rather than bleb formation, asthma involves airway hyperresponsiveness but not specifically blebs, and pneumonia is an infection in the lungs characterized by inflammation, typically without the formation of blebs.